Conventionally, there is known a teaching position correction device in a robot system which is configured to work on a work target object by using a robot, the teaching position correction device being for correcting a teaching position in a case where at least one of the robot and a holding device holding a work target object is relocated, so that an operation program which was taught before relocation can be used also after the relocation (for example, see Japanese Unexamined Patent Application, Publication No. 2005-149299).